2013 한국미생물학회연합 국제학술대회, 2013, 02, F039─F039

A deficiency of glycosyl hydrolase family 1 protein modulates the virulence of Streptococcus pneumoniae

Ji-Hye Kim, Sungkyoung Lee, Darum Lee, Seong-Han Kim, Misun Park, Songmee Bae

Abstract

Streptococcus pneumoniae causes frequently respiratory infections such as pneumonia and otitis media and occasionally is able to enter the bloodstream and develop into severe diseases such as bacteremia or meningitis. In our previous study, the tranion analysis between two phase variants of S. pneumoniae revealed enhanced expression level of the glycosyl hydrolase family 1 (GH1) in the opaque phase, a virulent form. To investigate a role of GH1 in pneumococcal disease, we constructed the GH1 mutant of S. pneumoniae D39 (serotype 2) by insertion-deletion mutagenesis replacing GH1 gene (SPD_0247) with erythromycin resistance gene cassette. For the biological characteristics, no significant difference was observed between GH1 mutant and wild type strain. In a murine model of pneumonia, the GH1 mutant exhibited the attenuation of virulence and more rapidly clearance in the lung. But the GH1 mutant remained the invasion ability into bloodstream, which was detected in blood after 24h of infections. We investigated the expression level of major virulence genes between GH1 mutant and wild type by the quantitative real time PCR. The GH1 mutant revealed the significant up-regulation of comABCD related to competence. These results suggest the potential of GH1 protein in the pathogenesis of S. pneumoniae.

• ISBN or ISSN: 0000-0000

• 본 연구는 질병관리본부 연구개발과제(과제번호 2012-N46003-00) 연구비를 지원받아 수행되었습니다.
• This research was supported by a fund(code 2012-N46003-00) by Research of Korea Centers for Disease Control and Prevention.